/*
	100% free public domain implementation of the SHA-1 algorithm
	by Dominik Reichl <dominik.reichl@t-online.de>
	Web: http://www.dominik-reichl.de/

	See header file for version history.
*/

#define _CRT_SECURE_NO_WARNINGS
#include "SHA1.h"

#ifdef SHA1_UTILITY_FUNCTIONS
#define SHA1_MAX_FILE_BUFFER 8000
#endif

// Rotate x bits to the left
#ifndef ROL32
#ifdef _MSC_VER
#define ROL32(_val32,_nBits) _rotl(_val32,_nBits)
#else
#define ROL32(_val32,_nBits) (((_val32)<<(_nBits))|((_val32)>>(32-(_nBits))))
#endif
#endif

#ifdef SHA1_LITTLE_ENDIAN
#define SHABLK0(i) (m_block->l[i] = \
	(ROL32(m_block->l[i],24) & 0xFF00FF00) | (ROL32(m_block->l[i],8) & 0x00FF00FF))
#else
#define SHABLK0(i) (m_block->l[i])
#endif

#define SHABLK(i) (m_block->l[i&15] = ROL32(m_block->l[(i+13)&15] ^ m_block->l[(i+8)&15] \
	^ m_block->l[(i+2)&15] ^ m_block->l[i&15],1))

// SHA-1 rounds
#define _R0(v,w,x,y,z,i) {z+=((w&(x^y))^y)+SHABLK0(i)+0x5A827999+ROL32(v,5);w=ROL32(w,30);}
#define _R1(v,w,x,y,z,i) {z+=((w&(x^y))^y)+SHABLK(i)+0x5A827999+ROL32(v,5);w=ROL32(w,30);}
#define _R2(v,w,x,y,z,i) {z+=(w^x^y)+SHABLK(i)+0x6ED9EBA1+ROL32(v,5);w=ROL32(w,30);}
#define _R3(v,w,x,y,z,i) {z+=(((w|x)&y)|(w&x))+SHABLK(i)+0x8F1BBCDC+ROL32(v,5);w=ROL32(w,30);}
#define _R4(v,w,x,y,z,i) {z+=(w^x^y)+SHABLK(i)+0xCA62C1D6+ROL32(v,5);w=ROL32(w,30);}

CSHA1::CSHA1()
{
    m_block = (SHA1_WORKSPACE_BLOCK*)m_workspace;

    Reset();
}

CSHA1::~CSHA1()
{
    Reset();
}

void CSHA1::Reset()
{
    // SHA1 initialization constants
    m_state[0] = 0x67452301;
    m_state[1] = 0xEFCDAB89;
    m_state[2] = 0x98BADCFE;
    m_state[3] = 0x10325476;
    m_state[4] = 0xC3D2E1F0;

    m_count[0] = 0;
    m_count[1] = 0;
}

void CSHA1::Transform(UINT_32* pState, const UINT_8* pBuffer)
{
    UINT_32 a = pState[0], b = pState[1], c = pState[2], d = pState[3], e = pState[4];

    memcpy(m_block, pBuffer, 64);

    // 4 rounds of 20 operations each. Loop unrolled.
    _R0(a, b, c, d, e, 0);
    _R0(e, a, b, c, d, 1);
    _R0(d, e, a, b, c, 2);
    _R0(c, d, e, a, b, 3);
    _R0(b, c, d, e, a, 4);
    _R0(a, b, c, d, e, 5);
    _R0(e, a, b, c, d, 6);
    _R0(d, e, a, b, c, 7);
    _R0(c, d, e, a, b, 8);
    _R0(b, c, d, e, a, 9);
    _R0(a, b, c, d, e, 10);
    _R0(e, a, b, c, d, 11);
    _R0(d, e, a, b, c, 12);
    _R0(c, d, e, a, b, 13);
    _R0(b, c, d, e, a, 14);
    _R0(a, b, c, d, e, 15);
    _R1(e, a, b, c, d, 16);
    _R1(d, e, a, b, c, 17);
    _R1(c, d, e, a, b, 18);
    _R1(b, c, d, e, a, 19);
    _R2(a, b, c, d, e, 20);
    _R2(e, a, b, c, d, 21);
    _R2(d, e, a, b, c, 22);
    _R2(c, d, e, a, b, 23);
    _R2(b, c, d, e, a, 24);
    _R2(a, b, c, d, e, 25);
    _R2(e, a, b, c, d, 26);
    _R2(d, e, a, b, c, 27);
    _R2(c, d, e, a, b, 28);
    _R2(b, c, d, e, a, 29);
    _R2(a, b, c, d, e, 30);
    _R2(e, a, b, c, d, 31);
    _R2(d, e, a, b, c, 32);
    _R2(c, d, e, a, b, 33);
    _R2(b, c, d, e, a, 34);
    _R2(a, b, c, d, e, 35);
    _R2(e, a, b, c, d, 36);
    _R2(d, e, a, b, c, 37);
    _R2(c, d, e, a, b, 38);
    _R2(b, c, d, e, a, 39);
    _R3(a, b, c, d, e, 40);
    _R3(e, a, b, c, d, 41);
    _R3(d, e, a, b, c, 42);
    _R3(c, d, e, a, b, 43);
    _R3(b, c, d, e, a, 44);
    _R3(a, b, c, d, e, 45);
    _R3(e, a, b, c, d, 46);
    _R3(d, e, a, b, c, 47);
    _R3(c, d, e, a, b, 48);
    _R3(b, c, d, e, a, 49);
    _R3(a, b, c, d, e, 50);
    _R3(e, a, b, c, d, 51);
    _R3(d, e, a, b, c, 52);
    _R3(c, d, e, a, b, 53);
    _R3(b, c, d, e, a, 54);
    _R3(a, b, c, d, e, 55);
    _R3(e, a, b, c, d, 56);
    _R3(d, e, a, b, c, 57);
    _R3(c, d, e, a, b, 58);
    _R3(b, c, d, e, a, 59);
    _R4(a, b, c, d, e, 60);
    _R4(e, a, b, c, d, 61);
    _R4(d, e, a, b, c, 62);
    _R4(c, d, e, a, b, 63);
    _R4(b, c, d, e, a, 64);
    _R4(a, b, c, d, e, 65);
    _R4(e, a, b, c, d, 66);
    _R4(d, e, a, b, c, 67);
    _R4(c, d, e, a, b, 68);
    _R4(b, c, d, e, a, 69);
    _R4(a, b, c, d, e, 70);
    _R4(e, a, b, c, d, 71);
    _R4(d, e, a, b, c, 72);
    _R4(c, d, e, a, b, 73);
    _R4(b, c, d, e, a, 74);
    _R4(a, b, c, d, e, 75);
    _R4(e, a, b, c, d, 76);
    _R4(d, e, a, b, c, 77);
    _R4(c, d, e, a, b, 78);
    _R4(b, c, d, e, a, 79);

    // Add the working vars back into state
    pState[0] += a;
    pState[1] += b;
    pState[2] += c;
    pState[3] += d;
    pState[4] += e;

    // Wipe variables
#ifdef SHA1_WIPE_VARIABLES
    a = b = c = d = e = 0;
#endif
}

// Use this function to hash in binary data and strings
void CSHA1::Update(const UINT_8* pbData, UINT_32 uLen)
{
    UINT_32 j = ((m_count[0] >> 3) & 0x3F);

    if ((m_count[0] += (uLen << 3)) < (uLen << 3))
    {
        ++m_count[1];    // Overflow
    }

    m_count[1] += (uLen >> 29);

    UINT_32 i;

    if ((j + uLen) > 63)
    {
        i = 64 - j;
        memcpy(&m_buffer[j], pbData, i);
        Transform(m_state, m_buffer);

        for ( ; (i + 63) < uLen; i += 64)
        {
            Transform(m_state, &pbData[i]);
        }

        j = 0;
    }
    else
    {
        i = 0;
    }

    if ((uLen - i) != 0)
    {
        memcpy(&m_buffer[j], &pbData[i], uLen - i);
    }
}

#ifdef SHA1_UTILITY_FUNCTIONS

//CRT_SECURE_NO_WARNINGS
#pragma warning(disable : 4996)

// Hash in file contents
bool CSHA1::HashFile(const TCHAR* tszFileName)
{
    if (tszFileName == NULL)
    {
        return false;
    }

    FILE* fpIn = _tfopen(tszFileName, _T("rb"));

    if (fpIn == NULL)
    {
        return false;
    }

    _fseeki64(fpIn, 0, SEEK_END);
    const INT_64 lFileSize = _ftelli64(fpIn);
    _fseeki64(fpIn, 0, SEEK_SET);

    const INT_64 lMaxBuf = SHA1_MAX_FILE_BUFFER;
    UINT_8 vData[SHA1_MAX_FILE_BUFFER];
    INT_64 lRemaining = lFileSize;

    while (lRemaining > 0)
    {
        const size_t uMaxRead = static_cast<size_t>((lRemaining > lMaxBuf) ?
                                lMaxBuf : lRemaining);

        const size_t uRead = fread(vData, 1, uMaxRead, fpIn);

        if (uRead == 0)
        {
            fclose(fpIn);
            return false;
        }

        Update(vData, static_cast<UINT_32>(uRead));

        lRemaining -= static_cast<INT_64>(uRead);
    }

    fclose(fpIn);
    return (lRemaining == 0);
}

#pragma warning(default : 4996)

#endif

void CSHA1::Final()
{
    UINT_32 i;

    UINT_8 finalcount[8];

    for (i = 0; i < 8; ++i)
        finalcount[i] = (UINT_8)((m_count[((i >= 4) ? 0 : 1)]
                                  >> ((3 - (i & 3)) * 8) ) & 255); // Endian independent

    Update((UINT_8*)"\200", 1);

    while ((m_count[0] & 504) != 448)
    {
        Update((UINT_8*)"\0", 1);
    }

    Update(finalcount, 8); // Cause a SHA1Transform()

    for (i = 0; i < 20; ++i)
    {
        m_digest[i] = (UINT_8)((m_state[i >> 2] >> ((3 - (i & 3)) * 8)) & 0xFF);
    }

    // Wipe variables for security reasons
#ifdef SHA1_WIPE_VARIABLES
    memset(m_buffer, 0, 64);
    memset(m_state, 0, 20);
    memset(m_count, 0, 8);
    memset(finalcount, 0, 8);
    Transform(m_state, m_buffer);
#endif
}

#ifdef SHA1_UTILITY_FUNCTIONS
// Get the final hash as a pre-formatted string
bool CSHA1::ReportHash(TCHAR* tszReport, REPORT_TYPE rtReportType) const
{
    if (tszReport == NULL)
    {
        return false;
    }

    TCHAR tszTemp[16];

    if ((rtReportType == REPORT_HEX) || (rtReportType == REPORT_HEX_SHORT))
    {
        _sntprintf(tszTemp, 15, _T("%02X"), m_digest[0]);
        _tcscpy(tszReport, tszTemp);

        const TCHAR* lpFmt = ((rtReportType == REPORT_HEX) ? _T(" %02X") : _T("%02X"));

        for (size_t i = 1; i < 20; ++i)
        {
            _sntprintf(tszTemp, 15, lpFmt, m_digest[i]);
            _tcscat(tszReport, tszTemp);
        }
    }
    else if (rtReportType == REPORT_DIGIT)
    {
        _sntprintf(tszTemp, 15, _T("%u"), m_digest[0]);
        _tcscpy(tszReport, tszTemp);

        for (size_t i = 1; i < 20; ++i)
        {
            _sntprintf(tszTemp, 15, _T(" %u"), m_digest[i]);
            _tcscat(tszReport, tszTemp);
        }
    }
    else
    {
        return false;
    }

    return true;
}
#endif

#ifdef SHA1_STL_FUNCTIONS
bool CSHA1::ReportHashStl(std::basic_string<TCHAR>& strOut, REPORT_TYPE rtReportType) const
{
    TCHAR tszOut[84];
    const bool bResult = ReportHash(tszOut, rtReportType);

    if (bResult)
    {
        strOut = tszOut;
    }

    return bResult;
}
#endif

// Get the raw message digest
bool CSHA1::GetHash(UINT_8* pbDest) const
{
    if (pbDest == NULL)
    {
        return false;
    }

    memcpy(pbDest, m_digest, 20);
    return true;
}
